1. Field of the Invention
The present invention relates to a sensor technology, particularly to a stimulus-based steering sensor device and a method for the same.
2. Description of the Related Art
The automobile is an electromechanical device controlled by the driver. Especially, the throttle and the steering system of an automobile must be controlled by the driver. Normally, the driver interacts with the throttle system and the steering system through the accelerator pedal and the steering wheel. Sometimes, the driver controls an automobile through a throttle controller and a steering controller, which can respectively measure the pedaling activity and the steering activity of the driver. The pedaling activity and the steering activity will cause the related shafts to rotate. An angle sensor device can measure the rotation angle of the related shaft and learn the extent of the pedaling or steering activity. A dedicated microcomputer can use the measurement results to physically control the automobile or assist the driver in controlling the automobile. Therefore, the angle sensor plays a very important role in automobiles.
The conventional angle sensors may be categorized into the contact type, the magnetic type and the resolver type. The contact type angle sensor is likely to wear in operation and hard to maintain its precision after long-term use. Besides, the operation of a contact type angle sensor needs an angle analysis program and is pretty complicated. The magnetic type angle sensor needs a magnet whose source and reliability is not always guaranteed. The current resolvers are normally used to detect the electrical angle of a motor or a single-revolution angle. No current resolver is used to detect a multi-revolution angle. A Taiwan patent of publication No. 201124699 disclosed a technology that uses two resolvers whose magnetic pole numbers are prime number to each other to measure angles, wherein the relationship between the mechanical angle and the variation of the electrical angle is used to implement angle conversion, whereby is obtained a real mechanical angle. However, the prior art cannot measure a multi-revolution angle but can only detect a single-revolution angle. Besides, very few current angle sensors incorporate a torque detection function needed by the emerging EPS (Electric Power Steering) system.
Accordingly, the present invention proposes a stimulus-based steering sensor device and a method for the same to overcome the abovementioned problems.